Tweaks for hotfix cherry-pick workflow (#4166)

Author: paulmedynski

.github/scripts/cherry-pick-to-release.sh

@@ -193,10 +193,29 @@ else
 
   lookup_milestone "${VERSION}"
 
+  # Build the PR body using printf to avoid quoting pitfalls with embedded
+  # newlines (mixed $'...' and '...' quoting can leave literal \n in output).
+  CONFLICT_BODY="$(printf '%s' \
+    "Cherry-pick of #${PR_NUMBER} (${MERGE_COMMIT_SHA}) into " \
+    "\`${TARGET_BRANCH}\` **failed due to merge conflicts**." \
+    "${MILESTONE_NOTE}" \
+    $'\n\nPlease resolve manually:\n```bash\n' \
+    "git fetch origin" \
+    $'\n' \
+    "git checkout ${CHERRY_PICK_BRANCH}" \
+    $'\n' \
+    "${CHERRY_PICK_CMD}" \
+    $'\n' \
+    "# resolve conflicts" \
+    $'\n' \
+    "git push origin ${CHERRY_PICK_BRANCH} --force" \
+    $'\n```')"
+
   gh pr create \
+    --draft \
     --base "${TARGET_BRANCH}" \
     --head "${CHERRY_PICK_BRANCH}" \
     --title "[${VERSION} Cherry-pick - CONFLICTS] ${PR_TITLE}" \
     ${MILESTONE_ARG} \
-    --body $'Cherry-pick of #'"${PR_NUMBER}"' ('"${MERGE_COMMIT_SHA}"') into `'"${TARGET_BRANCH}"'` **failed due to merge conflicts**.'"${MILESTONE_NOTE}"$'\n\nPlease resolve manually:\n```bash\ngit fetch origin\ngit checkout '"${CHERRY_PICK_BRANCH}"'\n'"${CHERRY_PICK_CMD}"$'\n# resolve conflicts\ngit push origin '"${CHERRY_PICK_BRANCH}"' --force\n```'
+    --body "${CONFLICT_BODY}"
 fi

.github/scripts/tests/cherry-pick-to-release.bats

@@ -296,3 +296,52 @@ STUB
   # Should have created an empty commit.
   grep -q "GIT: commit --allow-empty" "${STUB_DIR}/git.log"
 }
+
+@test "conflict PR body contains real newlines, not literal backslash-n" {
+  write_git_mock '
+    if [[ "$1" == "fetch" ]]; then exit 0; fi
+    if [[ "$1" == "cherry" ]]; then echo "+ abc123"; exit 0; fi
+    if [[ "$1" == "checkout" ]]; then exit 0; fi
+    if [[ "$1" == "rev-list" ]]; then echo "abc123def456 parent1"; exit 0; fi
+    if [[ "$1" == "cherry-pick" ]]; then
+      if [[ "$2" == "--abort" ]]; then exit 0; fi
+      exit 1
+    fi
+    if [[ "$1" == "commit" ]]; then exit 0; fi
+    if [[ "$1" == "push" ]]; then exit 0; fi
+    exit 0
+  '
+  # Capture the full --body argument to a file for inspection.
+  write_gh_mock '
+    if [[ "$1" == "api" ]]; then echo "7.0.1"; exit 0; fi
+    if [[ "$1" == "pr" && "$2" == "create" ]]; then
+      while [[ $# -gt 0 ]]; do
+        if [[ "$1" == "--body" ]]; then
+          printf "%s" "$2" > "'"${STUB_DIR}"'/pr-body.txt"
+          break
+        fi
+        shift
+      done
+      exit 0
+    fi
+    exit 0
+  '
+
+  run bash "${SCRIPT}"
+  [ "$status" -eq 0 ]
+
+  # The body file must exist (gh pr create was called with --body).
+  [ -f "${STUB_DIR}/pr-body.txt" ]
+
+  local body
+  body="$(cat "${STUB_DIR}/pr-body.txt")"
+
+  # Must NOT contain literal two-character sequence '\n'.
+  [[ "$body" != *'\\n'* ]]
+  # Each command in the code block must be on its own line.
+  [[ "$body" == *$'\ngit fetch origin\n'* ]]
+  [[ "$body" == *$'\ngit checkout dev/automation/pr-42-to-7.0.1\n'* ]]
+  [[ "$body" == *$'\ngit cherry-pick abc123def456\n'* ]]
+  [[ "$body" == *$'\n# resolve conflicts\n'* ]]
+  [[ "$body" == *$'\ngit push origin dev/automation/pr-42-to-7.0.1 --force\n'* ]]
+}